1. Field of the Invention
The present invention relates to a method of connecting and disconnecting a board in a hot state, i.e., while power is supplied thereto, and a device for executing the method.
Recent increases in the use of online computer systems have incurred a need to ensure the reliability of these systems, to enable a non-stop operation thereof. During such a non-stop operation, however, if a fault occurs in the system the faulty portion must be replaced by a standby device; that is, the faulty device is replaced by an operative device without switching the power supply to the system off. The purpose of the present invention is to enable the above procedure to be carried out.
2. Description of the Related Art
In a conventional method, a board (printed circuit board assembly) is connected and disconnected in a hot state as follows. Namely, when the board is connected to the system, the ground pins are first connected to the board and then the power source supply pins are connected, and accordingly, damage to and failure of elements (e.g., memory elements, etc.) mounted on the board are prevented. If a small current is flowing through the board and the pin current capacity is sufficient, the board continues to operate as usual when this method is applied.
Nevertheless, if the current capacity of one pin is not sufficient, and a plurality of power source pins must be used, when the board is connected to or disconnected from a mother-board through a connector(s), a simultaneous connection or disconnection of the plurality of pins cannot be carried out, and thus sometimes a large current flows through only one pin, whereby that pin is destroyed. Accordingly, conventionally, it is not possible to connect and disconnect a board through which a large current flows while the board is in the hot state.